LANSING, MI - The Michigan Supreme Court on Monday ruled that experts on false confessions can sometimes testify to jurors in criminal cases if their testimony is otherwise deemed reliable.

The ruling on the second to last day of the court's 2011-12 term was mostly a loss for a Livingston County man - Jerome Walter Kowalski - accused of killing his brother and sister-in-law in 2008.

The high court agreed 7-0 that a circuit judge and the state appeals court properly excluded the false-confession testimony of a psychologist called by Kowalski because it was unreliable.

It ruled 6-1, however, to reverse some of the reasoning behind the lower courts' decisions - that jurors already have "common knowledge" of false confessions and therefore do not need to hear expert testimony on it.

"The exclusion of such expert testimony when it meets all the requirements of our evidentiary rules could, in some instances, hinder the jury in its task because without the enlightenment of expert opinion the jury's ultimate determination may not be arrived at intelligently," Justice Mary Beth Kelly wrote in the lead opinion.

Despite the commonsense thinking that people do not make incriminating statements, she said, the trial judge and Court of Appeals "simply presumed that the average juror possessed the knowledge to evaluate factors that might lead to a false confession. This conclusion is not grounded in the necessary commonsense inquiry and lacks any legal basis."

The high court's ruling will serve as precedent for trial judges across Michigan mulling whether to admit expert testimony about false confessions. The justices said such testimony is admissible if the experts' data and methodology are reliable.

In May 2008, Richard and Brenda Kowalski were found shot to death in their Oceola Township home near Howell. Jerome Kowalski, of Warren, was questioned four times over several days and confessed during the last interrogation.

He initially described shooting his brother in the chest from several feet away but changed his account after a detective illustrated through role-playing that his first version of events did not corroborate evidence at the scene.

Seeking to call into question the confession - the primary evidence against him so far - Kowalski's lawyer tried to bring in testimony from Dr. Richard Leo and Dr. Jeffrey Wendt.

The decision to exclude Leo's testimony was a reasonable outcome, the justices ruled, because his research on police-interrogation techniques and their correlation to false confessions was prone to inaccuracy and bias and had not undergone peer review.

They sent the case back to the trial judge, though, to reconsider whether Wendt's testimony should be admitted. Wendt, a forensic psychologist, was to testify in part about Kowalski's psychological profile.

Kelly - along with Chief Justice Robert Young, Stephen Markman and Brian Zahra - also ruled that the defendant had no constitutional right to be able to use the false-confession testimony.

Michael Cavanagh, Marilyn Kelly and Diane Hathaway did not sign off on that finding but agreed with the result of the ruling.

Justice Stephen Markman, in a partial dissent, said jurors understand that people sometimes falsely confess and do not need to be told what they already know.

He warned that the ruling could lead to criminal trials increasingly becoming "a battle of psychologists."